A 56-year-old man has progressive fatigue and abdominal fullness. He has massive splenomegaly but no lymphadenopathy. CBC shows pancytopenia. Bone marrow aspiration yields a dry tap; biopsy shows interstitial infiltrates of cells with abundant cytoplasm and circumferential villous projections. The cells are tartrate-resistant acid phosphatase positive and express annexin A1. Best initial therapy?

• A Splenectomy
• B Interferon-alpha
• C Rituximab monotherapy
• D Cladribine ✓

Explanation

The findings are classic for hairy cell leukaemia: pancytopenia, massive splenomegaly without lymphadenopathy, dry tap, TRAP-positive hairy cells, and the highly specific marker annexin A1 (with CD11c, CD25, CD103). Single-agent purine analogue therapy with cladribine (or pentostatin) produces complete remission in most patients and is first-line. Splenectomy was historical palliative treatment and does not address marrow disease, so it is reserved for rare refractory situations such as life-threatening thrombocytopenia.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.